Anesthesiology

Postpartum tubal ligation

What the Anesthesiologist Should Know before the Operative Procedure

The postpartum period presents an optimal time for tubal ligation. The enlarged uterus facilitates access to the tubes, eliminating the need for a laparoscope and attendant risks. Furthermore, the patient is already in-house with a nursery typically available for care of the newborn.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

A postpartum tubal ligation is entirely elective. The only risk for delay is a subsequent pregnancy should the patient fail to obtain an “interval tubal ligation.” Since many physicians will not perform elective surgery for 6-weeks postpartum, by that time many postpartum patients will be unable to present for tubal ligation due to social or financial reasons. In at least one study, women who request a postpartum tubal and fail to receive it become pregnant within one-year at an alarming rate (47% vs 22% for those not requesting tubal ligation).

A significant barrier to the procedure is labor and delivery staffing. The ASA Practice Guidelines for Obstetric Anesthesia state, “the procedure should not be attempted at a time when it might compromise other aspects of patient care on the labor and delivery unit.” The American College of Obstetrics & Gynecology (ACOG), however, states: “Given the consequences of a missed procedure and the limited time frame in which it may be performed, postpartum sterilization should be considered an urgent surgical procedure.” They recommend considering performance of the procedure outside of labor and delivery.

2. Preoperative evaluation

Most postpartum women are healthy. The most common comorbities would be hypovolemia after a vaginal delivery, infection due to chorioamnionitis, diabetes, and preeclampsia.

Delaying surgery may be indicated if: the patient is febrile (e.g., chorioamnionitis or endometritis) and has not received antibiotics, is hemodynamically unstable due to blood loss or sepsis, has severe preeclampsia, has a residual nerve block (e.g., labor epidural removed day before, but continued weakness/numbness in lower extremities), or has received an anti-coagulant agent for thromboembolic prophylaxis.

3. What are the implications of co-existing disease on perioperative care?

b. Cardiovascular system

Acute/unstable conditions: Presence of these would preclude performance of this elective procedure.

Baseline coronary artery disease or cardiac dysfunction – Goals of management: A patient with significant cardiac history should have their tubal ligation performed at least 6-weeks postpartum when their cardiovascular physiology has returned to baseline. If the decision is made to proceed, the basic tenets of myocardial oxygen supply and demand hold: maintain a lower heart rate, sufficient diastolic blood pressure, and adequate oxygen delivery by hemoglobin and oxygen saturation. The wisdom of performing neuraxial anesthesia would depend on the cardiac dysfunction and the relative merits and risks of preload and afterload reduction.

c. Pulmonary

COPD: Highly unlikely in this population. Pulmonary testing is unnecessary.

Reactive airway disease (Asthma):

Perioperative Evaluation: Obtain history including medications, exacerbations, hospitalizations and perform a physical examination. Elective surgery should not proceed if there is a significant asthma exacerbation.

d. Renal-GI:

Postpartum patients retain many of the physiologic changes of pregnancy. Though the gastric angle should have returned toward normal, the time-frame for recovery from the progesterone-induced relaxation of the lower esophageal sphincter is unknown.

Perioperative evaluation – should be at least 8-hours since last intake of solids, and 2-hours for clear liquids. Even then, labor and analgesics can slow gastric emptying.

Perioperative Risk Reduction Strategies: Consider the use of metoclopramide, a clear antacid, and an H2 blocker. Neuraxial anesthesia is preferable, but never guarantees “avoidance” of the airway.

e. Neurologic:

Perioperative evaluation: If neuraxial anesthesia is planned, and several hours have passed since discontinuation of epidural analgesia, a general assessment of lower extremity sensation and movement is warranted. Vaginal delivery can cause nerve palsies that might erroneously blamed on the anesthetic.

Acute issues: If neuraxial anesthesia is planned, and several hours have passed since discontinuation of epidural analgesia, a general assessment of lower extremity sensation and movement is warranted. Vaginal delivery can cause nerve palsies that might be erroneously be blamed on the anesthetic.

The decreased neuraxial local anesthetic requirements characteristic of pregnancy remain in the first 36-48 hours post-delivery, so doses will be similar to those used for cesarean delivery.

Chronic disease: Indications/contraindications for neuraxial anesthesia are unchanged from the non-postpartum patient.

f. Endocrine:

Diabetes is a common condition in this population. Preoperative assessment and management of blood glucose is essential, especially while NPO, though tight control remains controversial.

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)

N/A

4. What are the patient's medications and how should they be managed in the perioperative period?

N/A

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

Anti-coagulant medications: As we become more concerned with postpartum DVT and pulmonary embolism, many hospitals have instituted pre-printed orders for low molecular weight heparin in patients at highest risk (obesity, postpartum). It is incumbent on the anesthesiologist to ensure these drugs have not been given in a timeframe that precludes neuraxial anesthesia (See the American Society for Regional Anesthesia guidelines).

i. What should be recommended with regard to continuation of medications taken chronically?

j. How To modify care for patients with known allergies –

l. Does the patient have any antibiotic allergies? (common antibiotic allergies and alternative antibiotics)

Postpartum tubal interruptions are generally performed without prophylactic antibiotics. If they are ordered, standard considerations regarding penicillin allergy and cross-reactivity with cephalosporins apply.

m. Does the patient have a history of allergy to anesthesia?

Malignant hyperthermia:

Documented- avoid all trigger agents such as succinylcholine and inhalational agents:

Proposed general anesthetic plan: TIVA with propofol and an opioid using a clean machine

Insure MH cart available: [- MH protocol]

Family history or risk factors for MH: as above

Local anesthetics/ muscle relaxants: Patients may describe a local anesthetic allergy that was actually local anesthetic toxicity or epinephrine injection during a dental procedure. If the allergy is well-documented, proceed with a local anesthetic from a different class (amide vs ester).

5. What laboratory tests should be obtained and has everything been reviewed?

No laboratory tests are required. If there was evidence of increased blood loss during vaginal delivery, a preoperative hemoglobin may be indicated, but if the patient is hemodynamically stable without tachycardia, the benefits of postpartum tubal ligation likely outweigh the risks.

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

Postpartum tubal ligation can be accomplished under epidural, spinal or general anesthesia. In fact, local with sedation is possible, but not desirable. Spinal anesthesia is most commonly used. It is performed in the supine position.

a. Neuraxial anesthesia is the preferred technique and is usually performed with minimal sedation, particularly in the nursing mother, although use of benzodiazepines or other medications is completely acceptable. The procedure is brief, therefore supplementing a marginal block with local, and sedation with intravenous opioids, nitrous oxide, or ketamine are reasonable.

Neuraxial

Benefits

Rapid recovery with minimal drugs that can cross into breast milk in the lactating patient.

Excellent analgesia and operative conditions

If the patient had a well-functioning labor epidural and delivered recently, the catheter can often be utilized.

Unlikely need for airway instrumentation, thus a lower risk of airway complications in the postpartum patient.

Drawbacks

Occasional protracted block resolution as we lack short-acting spinal agents without risk for transient neurologic symptoms (TNS). This can delay discharge from the PACU and even the hospital.

Reactivation of an existing labor epidural can fail with a prolonged anesthetic time attempting to achieve the appropriate level and density of block. In fact, in one study the cost for reactivation exceeded that of simply pulling the catheter and placing a spinal anesthetic. If the interval from delivery to reactivation exceeds 4-hours it may be preferable to proceed with spinal anesthesia.

Issues – investigate anticoagulation therapy that may have been instituted since delivery

b. General Anesthesia

Benefits

a secure airway in the postpartum patient whose stomach emptying may not be complete

better tolerance of the procedure for those with high anxiety state

Drawbacks

delayed cognitive awareness for care of newborn

agents traverse into breast milk at some concentration and can be transferred to the nursing infant, though this is of minimal concern during the colostrum phase.

Other issues

Airway concerns – pregnant women are known to have more difficult airway anatomy and more rapid desaturation with apnea due to swelling, breast engorgement, increased oxygen consumption, reduced functional residual capacity, and increased risk for aspiration.

c. Monitored Anesthesia Care

Benefits – none

Drawbacks – most obstetricians are not skilled in anesthetizing the multiple layers required for the procedure; furthermore toxic levels of local anesthetics are possible. The heavy sedation necessary is suboptimal in this population.

Other Issues

6. What is the author's preferred method of anesthesia technique and why?

In the patient with a well-functioning labor epidural, the epidural rate is turned down to 2cc/hr following delivery but not disconnected. The patient has several hours to bond with the infant, then the catheter is reactivated using carbonated 2% lidocaine with epinephrine or 3% 2-chloroprocaine for the surgery. If the patient is to undergo surgery the following day, the catheter is removed and a spinal is placed for the procedure in the OR. The only exception would be the patient who had an extremely difficult epidural placement in whom we would consider epidural reactivation even 12-24 hours after delivery.

What prophylactic antibiotics should be administered? – None

What do I need to know about the surgical technique to optimize my anesthetic care? – The procedure is performed with a sub-umbilical mini-laparotomy. Despite the low incision location, at least a T6 anesthetic level is desirable to avoid referred visceral pain from manipulation of the tubes.

What can I do intraoperatively to assist the surgeon and optimize patient care? The surgeon often requests Trendelenberg positioning and tilting of the table to each side to enhance visualization of the tube through the tiny incision.

What are the most common intraoperative complications and how can they be avoided/treated? Prioritize them by urgency.

Inadequate neuraxial anesthesia: can be supplemented with nitrous oxide by mask (MAC is reduced 40% so 50% nitrous provides significant analgesia) or ketamine IV since the procedure is generally short (20-30 minutes)

Inability to identify the tubes: patient positioning is all the anesthesia provider can do

Intraoperative hemorrhage: may require conversion to a larger incision and general anesthesia.

a. Neurologic:

N/A

b. If the patient is intubated, are there any special criteria for extubation?

Standard extubation criteria apply.

c. Postoperative management

The pain from BTI is out of proportion to the size of the incision, but generally of short duration.

What analgesic modalities can I implement? Neuraxial morphine is advocated by some, however many patients will be discharged home in less than 24-hours and the risk of delayed respiratory depression might preclude its use. Encouraging the surgeons to place local anesthetic at the tube stumps, fascia and skin may reduce postoperative pain. Oral analgesics are standard.

Surgical complications are rare. Infection and intraoperative or delayed bleeding can occur. Perhaps considered a complication, later maternal regret for having the procedure increases over time and is especially common in younger women or those experiencing a major life change.